


White Hot Flames

by HouseWarcraft



Category: Ao no Exorcist | Blue Exorcist
Genre: Demons, Eventual Romance, F/M
Language: English
Status: In-Progress
Published: 2017-05-21
Updated: 2017-05-21
Packaged: 2018-11-03 04:34:19
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,260
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10959750
Author URL: https://archiveofourown.org/users/HouseWarcraft/pseuds/HouseWarcraft
Summary: New to the Japan district, Calista is given the mission to keep a close on the Sons of Satan, to make sure they don't lose control...and to kill them if necessary. But can she do her duties, while keeping her cover and feelings in check? Takes place two months after season 1 ending. Rating may change as story develops.





	1. Chapter 1

This would be the first time she's ever been outside of Rome. While she was excited for the change in scenery, Calista wasn't here to sight see. No, she'd been given a mission to keep a close eye on a pair of demons working as exorcists inside the True Cross Order. Rin Okumura and his twin brother Yukio. Both were considered dangerous and unpredictable. Why she'd been chosen for this mission she didn't understand. Maybe it was because she was their age and half demon herself? Regardless, she had a job to do and she would see it through. If she found that either boys were a threat, she was to eliminate them immediately. Even though they already had more than one exorcist watching over them, they were now considered to be too close to the boys to perform their duties, should they need to be killed.

So they sent her with strict orders not to reveal herself to them.

She stood outside of True Cross Academy, starring up at the enormous school and wondered how anyone could possibly navigate their way around such a place. Was all of this really necessary? It seemed a little excessive to her.

"Seems like someone is compensating for something to me." Rolling her eyes, Calista readjusted the shoulder strap of her backpack. "Can't believe I have to attend school here and go through cram school all over again." Shaking her head as she spoke to herself, Calista made her way towards the huge school where she would get her classes and dorm room. First she needed to see Mephisto, the principal of this school and the only one who was to know of her involvement here.

It took her over an hour to find his office...having to ask more than once for directions. When she finally comes to her destination, she wasn't in the greatest of moods. Without bothering to knock, she enters the room, her aquamarine eyes blazing with annoyance. "Could you have made this place anymore confusing?!"

He looked up at her with his green eyes, just as annoyed by her barging in as she was by how confusing his school was. "My girl, it is rude to enter before knocking. Didn't they teach you any manners in Rome?"

"Oh shut it," She dropped her backpack on the ground beside a chair, before sitting down, crossing her legs. "You know why I'm here, and you know you're not to speak a word of my presence to anyone."

He waves a hand dismissively, passing a square piece of cheese to a little green hamster. "Yes, yes, of course. The Okumura brothers have no idea you're coming or your involvement with the Order. The only one who knows you're coming is Yukio, who is expecting a new student this afternoon. As I do not have any open rooms in the girls dorm, you will have your own separate room in the Okumura's building. I hope that will suffice?"

"Yeah, that'll be fine. This way I can keep a better eye on them without appearing suspicious." She stands back up, lifting her bag as she does. "As you well know, the Vatican doesn't trust you or them. That's why they sent me."

Mephisto held out a key that would allow her to access the cram school. "Of course, my dear, but I do wonder..."

"What's that?" She glanced back at him over her shoulder after taking the key and turning back towards the door.

"If they truly trust you, as you seem to think they do. Especially since you're no ordinary demon.~"

Calista didn't bother to answer him, instead her eyes narrowed into a glare.

She found the dorm building fairly easy. Then again it was the only building on the whole property that looked like it should be completely abandoned. The fact that it wasn't, was mind boggling. "You're kidding me? Students actually live in this dump? The whole place should be condemned!"

"Where do you get off on calling our building a dump?" The irritated voice behind her, announced the presence of another.

Turning around, Calista came face to face with who she suspected to be one half of the Okumura brothers. The one in front of her had dark blue/black hair and blue eyes. What stood out though, was the pointed demon ears, long black demon tail, and pointed fangs which were currently bared at her.

Before she addressed him, she had to remember to keep her cool and not give herself away. "Sorry," she apologized, giving him a small smile. "I didn't mean to offend you. I'm new here and just didn't expect to be placed in this dorm building."

He glared at her a moment more, as if he were trying to get a read on her. "My brother and I are suppose to be the only ones in this building."

She nods her head. "Yes, I was told that there weren't any empty dorms available in the girls building, so the principal placed me here until further notice." Remembering the custom in Japan was to bow when greeting someone, Calista quickly does so, so as not to further offend him. "My name is Calista and I just transferred here from Rome. I'm to start the cram school today as well."

His eyes seemed to widen a bit as she mentioned this. "So you're going to be an Exorcist too?" He smiled and uses his thumb to point at himself. "I'm Rin Okumura and I'm an Exorcist too!"

So this was the older brother then? She heard about him. Unlike his younger brother, Rin had been born with Satan's blue flames and struggled to control them, having already lost himself once before. This was the one that needed watching over the most.

"It's a pleasure to meet you, Rin." She looked down at her watch on her left wrist, checking the time. "Hey, do you think you could help me get to the cram class? I was given this key, but I'm afraid I'm terrible at directions." Which wasn't a lie, like earlier, she was easily lost. Especially in new places.

"Yeah! Sure! No problem. I was just on my way there now in fact." He walks to the door of the building, slipping the key into the lock and turning it. When he opened the door, it led into a hallway that didn't look like it belonged inside the building the door was attached to. "My little bro Yukio is our teacher."

"Mr. Okumura is expecting me, though I haven't had the pleasure of meeting him yet." As Rin enter the hallway, Calista followed behind him.

"He's alright, I guess. A bit of a know-it-all." Rin shrugged his shoulders, leading the way.

"I've heard he's a genius. One of the few to become an Exorcist at such a young age. A prodigy, so to say."

"Yeah, I guess so." He seemed a bit annoyed by this, placing his hands behind his head. "But he's not all that. I'll catch up to him before he even realizes it."

She felt his presence before she heard speak up behind them. "You have a long way to go before you catch up to me."

Both Calista and Rin paused in their tracks, turning around to face the one who'd spoken. As Calista looked at the boy behind her, using his finger to push his glasses back up, she instantly knew that this was the other brother; Yukio Okumura. His eyes were a deeper shade of teal than hers. Paler than his older brother, but taller and more mature looking. Beneath his left eye were two moles, and one under the right side of his lips. A pair of pointed demon ears poked out from beneath his dark brown hair and she could only assume that his tail was carefully tucked away under his True Cross Order uniform; unlike his brother who left it exposed. There was no denying that there were major differences between these twins. She could tell that in just the few minutes of being around them.

"Yeah, well, you heard me. I will catch up to you sooner than you think!" Rin stated confidently.

Though he went unnoticed, Yukio's attention on her. Earlier, Rin had watched her closely, but seemed to quickly dismiss her, whereas Yukio's eyes seemed to try and see right down to her soul. It was a bit unnerving, but she wouldn't let it break her resolve.

"You're the new student then, from the Rome district." He said it matter-of-factly, like a true instructor.

Calista nods and like with Rin, she bowed to him. "That's right. I'm Calista, recently transferred here. It's a pleasure to meet you, Mr. Okumura, I look forward to learning under you."

Yukio watched her a moment longer. She could tell he was suspicious of her. Which he had every right to be. She'd be suspicious too. "Very well, you're both late, so let's get in and get started." He pushed his glasses once more as he moved between her and Rin and into the class room.

Calista stood there for a second, Rin going on ahead of her and following his brother into the classroom, grumbling. So those were the Okumura Brother's. Rin would be easy enough to keep her cover around, but Yukio….well he would be a bit more challenging. She smirks to herself, and as she did, a pair of sharp canine fangs glinted in the low light, the thought of a challenge exciting to her. It had been a long time since anyone or anything had made her this excited.

Hiding her fangs, she too followed the twins into the classroom; eager to see how this mission would turn out.


	2. Chapter 2

Deciding that it was probably better for her to sit in the back of the classroom away from the other students, and away from the Okumura Brothers, Calista found an empty table that she would have all to herself. This way she wasn't right in their line of sight and likely to be forgotten rather easily. As the afternoon went on, she had to hand it to the youngest of the twins, Yukio was actually a pretty good teacher, keeping the attention of most everyone. Rin on the other hand, seemed to fall asleep more than he actually paid attention. It was a wonder that he'd made it this far.

Still, she couldn't blame him. Yawning, she leaned on her propped up hand. Of course she already knew all of this and because of her prior knowledge, found this whole thing to be rather boring. _"Ugh…when is it over?"_ She found myself thinking more than once.

"I think that will be all for today class." Calista heard Yukio say from the front of the class. When she lifted her head, she saw him packing the suitcase he'd brought in with him.

"Finally..." She whispered to herself, standing up and pulling her backpack on to her shoulder. She was ready to leave and get back to the dorm. By now her things should have been brought over from her own dorm in Rome. She could really use a hot bath and a soft bed. The time difference was finally catching up to her and she was more than a little exhausted.

Without even speaking to the other students, though she could feel their curious eyes on her, she left the classroom and headed down the hallway. Reaching into her pocket, she wrapped her hand around the key, Mephisto gave her earlier that day. It should lead her back to the dorms just like when Rin had opened up the door to the cram school.

Just as she was pulling the key out of her pocket, she heard someone behind her calling her name. She could only assume that it was one of the twin brothers, seeing as she didn't remember giving her name to anyone else. Pausing, she turns around to see that Yukio was waving her down and making his way towards her.

_"Great, what does he want?"_ She thought to herself, putting on a fake smile before addressing him. "Hey there, Teach. Good class today, learned a lot. You're pretty good at this by the way." Her aquamarine eyes, looked up into his teal ones.

"Why were you sent to Japan, Miss..." He trailed off, realizing that she'd never given him her last name.

"Just Calista, I don't have a last name." As she informed him of this, the look of shock in his eyes didn't go unnoticed, so she explained a little further. "I was found as a baby and raised in an orphanage. They never bothered to give me any more than a first name." She shrugs her shoulders. "It doesn't exactly bother me either. So please, just call me Calista, besides, there's no need to be so formal."

He frowned, but seemed to accept this as he pushed up his glasses and nodded. "Very well then, but my question remains the same. Why were you transferred here?"

Time to make up another lie.

"You see, I have no idea why I was sent here." She said, "I was told that they could no longer house me in Rome and would instead be sending me to Japan. Why here of all places, I couldn't tell you. I was studying to be a tamer and will continue to do so here."

"A tamer, I see." He nods his head and continued talking, though she wasn't exactly paying attention, taking the moment to take in his features a bit more.

He and his twin brother shared very little of the same facial features; other than the demonic ones. His skin much paler than Rin's and there was a maturity in his eyes that Rin didn't have. He was much taller too; practically towering over her. Despite the moles on his face, it didn't distract from the fact that Yukio was a good looking guy. His eyes alone were beautiful. If it weren't for the stoic expression on his face, he'd be even more good looking than his older brother.

Shaking her head, she tries to erase the thought from her mind. She wasn't here to appreciate their good looks, she was here on a specific mission and she couldn't let herself become distracted. No matter what she need to keep her mind focused on the mission at hand. These two were the sons of Satan himself. They have both already lost themselves to Satan's powers, and Yukio has been possessed once already by the Dark Lord himself. What's to say it wouldn't happen again? She needed to remain vigil.

_"Get it together, Calista!"_ She yelled to herself. Tilting her head up, she looked him in the eyes. "Yep, got it! Can I go now? I'm expecting my things to have arrived from Rome and I want to get a bath and unpacked before going to sleep."

* * *

**Yukio's PoV**

_"Had she even been listening?"_ Yukio thought to himself as he looked down at the new student who joined his class this afternoon. Mephisto had told him just two days ago that he would there would be a new student coming from Rome. Hearing that they would be from Rome, Yukio instantly suspected that the Vatican was sending someone to keep a closer eye on him and his brother. Looking down at the girl in front of him, he wasn't so sure now.

She looked around their age, maybe a year younger even. Not very tall either, much shorter than he was by far. Though, he did catch something about her that wasn't exactly usual. Underneath her jet black hair, he caught a pair of small pointed ears, much like his and his brothers. Was she part demon too? His speculation made him study her feature even more closely. Even though her ears were pointed, she didn't appear to have any more demonic traits. If she had a tail, she was keeping it well hidden, and she was careful when she talked too. If there were any fangs, she wasn't showing them off. Her eyes though...they were the lightest shade of aquamarine that he had ever seen.

Before he could question whether she'd heard him or not, Calista had turned around and placed the key in the lock, turning it and opening the door that would lead back to the dorms and going through. When she left the door open, he figured it was because she was sharing the building with him and his brother. Sighing heavily, Yukio using his finger to push up his slipping glasses. This girl was a total mystery. He wasn't buying any of it. There had to be a reason why Rome had sent her here? He just needed to figure it out.

Someone slapped him hard on the back, pulling his mind back into reality and forcing his glasses to slide down on his nose once more. "Whatcha standing around for, little bro?" Rin's voice asked as his arm came around Yukio's shoulders. He looked through the open door, watching a moment as the new girl walked down the hallway of their building. A mischievous grin pulled at his lips, showing off the pointed caines. "Ohhh I see." He chuckled. "You're checking out the new girl, aren't ya.~"

Annoyed, Yukio's brow twitched. "It's not like that!" He yelled at his older brother, once more fixing his glasses. "I was just wondering why she was sent here. It's a bit suspicious." He then said in a calmer voice. "Never mind, let's go." Shrugging off Rin's arm, he moved forward through the door and back into their dorm building.

"What's gotten into him?" Rin questioned as he watched his little brother walk off, following the new girl into the dorm. Shrugging his shoulders, he follows along too, closing the door behind him as he does.

* * *

**Calista's PoV**

By the time she had bathed and unpacked most of her stuff, it was well after sundown. Sitting on her now made bed, she looked down at the black and red hound laying by her feet. She had been telling Yukio the truth when she said she was studying to be a tamer...Well half truth anyway. She was already a full fledged Exorcist and Tamer and the hound at her feet was her familiar, Cerberus; named after the Greek hellhound who guarded the underworld. He didn't have three heads like the hound of myth, but he was a demon hound and she found it funny to name him after the legendary hound. Her Cerberus however, had black fur, tinged with red, his ears and tail crimson at the tips. He closely resembled the doberman breed. He was a bit of a pain in the butt at times, but he's been with her for years now and she loved him all the same. He was her closest friend and companion.

After she unpacked most of her stuff, she used the summoning tattoo on the underside of her wrist to summon him to her. It was easier than trying to explain him right away to a bunch of people she'd never met, and even harder still to explain to her teacher that she'd mastered summoning her familiar already when she was suppose to be a newbie. She'd just use summoning papers to bring him to her when she was around everyone else. If things ever got hairy and her paper weren't within reach or destroyed, she could use the tattoo on her wrist, and risk explaining if the time came.

Reaching a hand down, she lightly patted him on the head, rubbing his ears. He lifted his head and looked up at her with his dark, red eyes. _"Why are we here again?"_ He asked her. Because she was a demon, she could hear him and easily communicate.

"You know why we're here, now keep your mouth shut about it. Our targets are both demons and will be able to hear you when you talk to me. We have to keep our mission to ourselves. No one is to know about it." She glared back down at him, trying to appear fierce, but failing when her stomach gave a loud growl.

_"You're hungry...when was the last time you had something to eat?"_ There was a look of concern in his eyes. He tended to worry about her wellbeing, which was a good thing, because she didn't do the best job of looking after herself.

Calista tapped her chin in thought. "I think I had something earlier this afternoon before coming here. A bag of chips, I think. It wasn't much, I know that. I should probably go down and find something more to eat." Getting to her feet, she walks over to the door, slipping her feet into a pair of black flats.

Behind her, Cerberus stood up and glared at her, growling low in his throat. _"You know what I'm tal-"_

"Are coming along? I'm sure you're just as hungry as I am?" She asked, cutting him off mid sentence. Before he had the chance to question her again, Calista opened the door and walked out of her room. As she entered the hallway, the smell of something cooking immediately caught her attention. Her mouth watered and she follows the scent all the way down the hall until she came upon the kitchen.

Peeking around the corner, she looked into the kitchen. She saw several tables with chairs, but what surprised her was Rin Okumura was standing in the middle of the kitchen, moving back and forth, cooking something and working his butt of doing it. "I had no idea he could cook..." She whispered to herself. Upon closer look, she could see that he wasn't alone. On his shoulders sat a two tailed cat, and on the counter was a purple, satyr-like, demon.

Her stomach growled again, and when it did, the cat sitting on his shoulders turned his head and looked back at her, meowing he pawed at Rin's cheek. _"Rin, someone's watching from the hallway."_ She heard him saying.

"Huh?" Rin questioned, looking back at the cat, before looking over his shoulder. Catching sight of her standing there, he smiled and waved her in. "Come on in, it'll be done here soon." He said this rather excitedly.

Deciding to go with it, Calista entered the kitchen and took a seat at the counter that looked into the cooking area. As she sat down, she noticed that Cerberus had in fact, followed her. When she looked down at him, he was glaring at her. She knew what he wanted to say, but was glad that he kept his mouth shut. Turning her attention back to Rin, she questioned him about what he was make. "So, what are you cooking?"

He grins from ear to ear. It was obvious by his expression that whatever he was making was something he was proud of. "Since you're new here and all, I thought it would be a good idea to make my favorite; sukiyaki!"

"Suki...yaki?" She was a bit confused, having no idea what kind of meal this was. Having been born and raised in Rome, Calista was more use to Italian foods than Japanese. Only having Chinese fried rice, or noodles every now and then. Her extent of Japanese food was what she saw in anime and that was mostly ramen, which was available in supermarkets around the world. This, sukiyaki, was completely new to her. But she wasn't a picky eater and would try anything once.

"Yep!" His smile widens even more. "It's amazing, you're gonna love it!"

Calista chuckles a bit at his enthusiasm. "I'll take your word for it." Looking around the kitchen, she wondered where the younger of the twins could be. "So, where's Yukio? Shouldn't he be here to eat dinner too?" Absently, she places her hand on the top of Cerberus's head, lightly petting him as she talked.

By now, Rin had turned around and went back to his cooking. "I think he said something back taking a bath." He shrugged his shoulders. "I'm sure he'll be here later on." As Calista nods her head, Rin went on to ask a question of his own. "So, were you sent here to watch over my brother and I?" He asked this without even turning around to look at her.

The hand petting Cerberus immedately paused, but her expression remained the same. "What? No, of course not. It's like I told Yukio, they were unable to continue housing me and sent me here. It's not like I had a choice in the matter." She propped her elbow on the counter, placing her cheek on her hand, trying to take on a "bored" look. Maybe it wasn't going to be so easy fooling either of them after all?

"Good," His voice took on a more menacing tone. "If you were here to hurt my brother," He turned around and there was a look in his eyes that sent a shiver down her spine. "Then I'd have to kick your ass." Rin made no mention of himself, only that of Yukio, like a good older brother would. If it had been anyone else, she might have laughed at him, but the look in his eyes, the tone of his voice, and the fact that he was Satan's son, kept her from feeling any kind of amusement. He meant every word that he said.

She'd have to tread carefully...


End file.
